Huu Nghi, T., & Huynh Hong Nga, N. (2026). FACTORS INFLUENCING VIETNAMESE EFL TEACHERS’ PROFESSIONAL DEVELOPMENT: A QUALITATIVE STUDY IN THE MEKONG DELTA. HNUE Journal of Science: Journal of Educational Science, 71(1), 107-117. https://doi.org/10.18173/2354-1075.2026-0011